Pale yellow dune moth (Copablepharon grandis) COSEWIC assessment and status report: chapter 11

Technical Summary

Copablepharon grandis

Pale Yellow Dune Moth  – Noctuelle jaune pâle des dunes

Range of Occurrence in Canada:

southern Alberta, Saskatchewan, Manitoba

Extent and Area Information

Extent of occurrence (EO) (km²)

maximum of 184,590 km² in Canada
(based on distribution records)

Specify trend in EO 

apparently declined over past 100 years

Are there extreme fluctuations in EO?

No

Area of occupancy (AO) (km²)

maximum possible 203 km² <50 km² based on 2X2 grid

Specify trend in AO

Likely declining

Are there extreme fluctuations in AO?

No

Number of known or inferred current locations

10 known in Canada; 84 globally

Specify trend in #

decline, not seen in southern Alberta since 1913

Are there extreme fluctuations in number of locations?

No

Specify trend in area, extent or quality of habitat 

declining

Population Information

Generation time (average age of parents in the population)

1 year

Number of mature individuals

Not estimated

Total population trend:

Not known; possible decline

% decline over the last/next 10 years or 3 generations.

Not known

Are there extreme fluctuations in number of mature individuals?

Unknown; likely

Is the total population severely fragmented?

Patchily distributed because of habitat

Specify trend in number of populations

Not known; possible decline

Are there extreme fluctuations in number of populations?

No

Threats (actual or imminent threats to populations or habitats)

  1. Sand dune stabilization is an ongoing threat.
  2. Heavy cattle grazing is likely detrimental to the species.
  3. Land development will in most cases make the habitat unsuitable.
  4. Recreational use will have a negative effect unless it is of minimal intensity.
  5. Demographic collapse remains a possibility in isolated populations.

Rescue Effect (immigration from an outside source)

Status of outside population(s)?

USA: >60 locations known; likely with similar trends to those in Canada

Is immigration known or possible?

Unlikely without intervention but some US areas poorly inventoried

Would immigrants be adapted to survive in Canada?

Yes, likely

Is there sufficient habitat for immigrants in Canada?

Yes, but declining

Is rescue from outside populations likely?

Unlikely

Quantitative Analysis

Not undertaken (limited data)

Current Status

COSEWIC: Special Concern (November 2007)

Status and Reasons for Designation

Status: Special Concern

Alpha-numeric code: Not applicable

Reasons for Designation: Although the area of occupancy is small and there is some evidence of decline in its extent of occurrence and area of occupancy, the species persists in widely separated dune systems, the declines are not well documented, and the status of threats is unclear.  It requires semi-stable sand dunes which are declining.

Applicability of Criteria

Criterion A: (Declining Total Population): No data
Criterion B: (Small Distribution, and Decline or Fluctuation): 2- Area of occupancy is small; a) severely fragmented but is likely to be found at some additional locations; b) continued decline is insufficiently documented.
Criterion C: (Small Total Population Size and Decline): Total population unknown but not likely to be below 10,000.
Criterion D: (Very small Population or Restricted Distribution): Total population more than 1000 and area of occupancy not as restricted as required under the definition.
Criterion E: (Quantitative Analysis): No quantitative analysis undertaken.

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